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Biomedical subjects

L Kurland

Publications and source records attributed to L Kurland.

12 recordsLinked to original sources

Gender-specific association between preproendothelin-1 genotype and reduction of systolic blood pressure during antihypertensive treatment--results from the Swedish Irbesartan Left Ventricular Hypertrophy Investigation versus Atenolol (SILVHIA).

BACKGROUND: Studies suggest that endothelin-1 contributes to the pathogenesis of hypertension. A G5665T gene polymorphism of preproendothelin-1 has been shown to be associated with higher blood pressure in overweight patients. No study has yet determined the effect of this polymorphism on the change in blood pressure during antihypertensive treatment. HYPOTHESIS: This study aimed to determine this effect in hypertensive patients with left ventricular (LV) hypertrophy during antihypertensive treatment with either irbesartan or atenolol. METHODS: We determined the preproendothelin-1 genotype using minisequencing in 102 patients with essential hypertension and LV hypertrophy verified by echocardiography, randomized in a double-blind fashion to treatment with either the AT1-receptor antagonist irbesartan or the beta1-adrenoceptor antagonist atenolol. RESULTS: The change in systolic blood pressure (SBP) after 12 weeks of treatment was related to the preproendothelin-1 genotype in men; after adjustment for potential covariates (age, blood pressure, and LV mass index at study entry, dose of irbesartan/atenolol, and type of treatment), those carrying the T-allele responded on average with a more than two-fold greater reduction than those with the G/G genotype (-21.9 mmHg 13.9] vs. -8.9 [2.3], p = 0.007). No significant differences in blood pressure change between G/G and carriers of the T-allele were seen among women. CONCLUSIONS: Our finding suggests a gender-specific relationship between the G5665T preproendothelin-1 polymorphism and change in SBP in response to antihypertensive treatment with irbesartan or atenolol, suggesting the endothelin pathway to be a common mechanism included in the hypertensive action of the drugs.

Antihypertensive Agents↗

Beta1-adrenergic receptor gene polymorphisms and response to beta1-adrenergic receptor blockade in patients with essential hypertension.

BACKGROUND: Studies suggest that the Ser49Gly and Arg389Gly polymorphisms in the beta1-adrenergic receptor might be of functional importance for the cardiovascular system. Both have been associated with altered receptor activity in vitro, and with hypertension and cardiac failure in vivo. HYPOTHESIS: The aim of this study was to test whether these polymorphisms were associated with the change in heart rate or blood pressure in patients with essential hypertension and left ventricular (LV) hypertrophy treated with the beta1-adrenergic receptor blocker atenolol. METHODS: Blood pressure and heart rate were measured in 101 hypertensive patients with echocardiographically verified LV hypertrophy, randomized in a double-blind study to treatment with either the beta1-adrenergic receptor blocker atenolol or the angiotensin II type I receptor antagonist irbesartan. Changes in blood pressure and heart rate were evaluated after 12 weeks. Beta1-adrenergic receptor genotyping was performed using polymerase chain reaction and restriction fragment length polymorphism. RESULTS: We found no significant associations between the changes in the measured variables and either of the two polymorphisms. However, carriers of the 49Gly allele showed a tendency toward a greater reduction in heart rate compared with patients with the Ser/Ser49 genotype (p = 0.06). CONCLUSIONS: The Ser49Gly and Arg389Gly beta1-adrenergic receptor polymorphisms do not seem to exert a major effect on the changes in heart rate and blood pressure during 12 weeks of treatment with atenolol in patients with essential hypertension and LV hypertrophy.

Adrenergic beta-Antagonists↗

The antihypertensive response to irbesartan treatment from a pharmacogenetic perspective.

Coronary heart disease is the leading cause of death in the Western world. Approximately half of all the people who have their 1st heart attack and 2/3 of those with their first stroke have high blood pressure levels. Hypertension affects approximately 25% of the adult population. By treating hypertension and risk factors that contribute to cardiovascular disease both mortality and morbidity can be reduced. Many drugs have proven to be effective in treating hypertension, although the individual patient's response to antihypertensive treatment varies over a wide range and cannot be predicted with methods used today. Between 30-60% of the blood pressure variation is determined by genetic factors. Also the variation in drug response is in part heritable, which defines pharmacogenetics. This review gives a general background to pharmacogenetics and its potential usage. In addition, results from recent pharmacogenetics studies on the antihypertensive effect of the angiotensin II type 1 receptor antagonist irbesartan are presented.

Antihypertensive Agents↗

Polymorphisms in the renin-angiotensin system and endothelium-dependent vasodilation in normotensive subjects.

BACKGROUND: Our aim was to test the hypothesis that genes encoding components in the renin-angiotensin system influence endothelial vasodilatory function. METHODS: In 59 apparently healthy, normotensive individuals, endothelium-dependent vasodilation (EDV) and endothelial-independent vasodilation (EIDV) was evaluated by infusing metacholine and sodium nitroprusside into the brachial artery. Forearm blood flow was measured by venous occlusion plethysmography. The ACE insertion (I)/deletion (D) polymorphism, the T174M and M235T angiotensinogen restriction fragments length polymorphisms, the angiotensin II receptor type 1 (AT1R) A1166C, and the aldosterone synthase gene (CYP11B2) C-344T polymorphisms were analysed. RESULTS: When analysing the ACE, the two angiotensinogen and the aldosterone synthase CYP11B2 genotypes independently, no significant association with endothelial vasodilatory function was found. However, a significant reduction in endothelium-dependent vasodilation was observed in the subjects (n=9) with the ACE D allele and the angiotensinogen T174M genotype (P<0.05). Subjects with the AT1R genotype AC showed a reduction in both EDV (P=0.05) and EIDV (P=0.04) when compared with those with the AA genotype. CONCLUSIONS: The subjects with the ACE D allele in combination with the angiotensinogen T174M genotype are associated with a reduced EDV. This together with the observation that the AC AT1R genotype is associated with a reduction in both EDV and EIDV, supports the hypothesis that endothelial vasodilatory function is influenced by genes in the renin-angiotensinogen system.

Adult↗

Angiotensin converting enzyme gene polymorphism predicts blood pressure response to angiotensin II receptor type 1 antagonist treatment in hypertensive patients.

OBJECTIVES: To determine whether polymorphisms in the renin-angiotensin system can predict blood pressure-lowering response to antihypertensive treatment; more specifically, in response to treatment with irbesartan or atenolol. DESIGN AND METHODS: Eighty-six patients with hypertension were randomized to double-blind treatment with either the angiotensin II type 1 receptor antagonist irbesartan or the beta1 adrenergic receptor blocker atenolol and followed for 3 months. We analysed angiotensinogen T174M and M235T, angiotensin converting enzyme (ACE) I/D and angiotensin II type 1 receptor A1166C polymorphisms and related them to blood pressure reduction. RESULTS: The mean reductions in blood pressure were similar for both treatments. In the irbesartan group, individuals homozygous for the ACE gene I allele showed a greater reduction in diastolic blood pressure, exceeding those with the D allele (-18 +/- 11 SD versus -7 +/- 10 mmHg, P = 0.0096). This was not the case during treatment with atenolol, and the interaction term between type of treatment and ACE II genotype was significant (P = 0.0176). The angiotensinogen and angiotensin II type 1 receptor polymorhisms were not related to the response to treatment. CONCLUSIONS: ACE genotyping predicted the blood pressure-lowering response to antihypertensive treatment with irbesartan but not atenolol. Thus, specific genotypes might predict the response to specific antihypertensive treatment.

Adrenergic beta-Antagonists↗

Impairment, disability, and handicap in multiple sclerosis: a population-based study in Olmsted County, Minnesota.

We studied functional status of MS patients in a geographically based cohort in Olmsted County, Minnesota. The 162 definite MS patients who were alive and residing in the study area on December 1, 1991, constituted the MS prevalence disability cohort. We identified 179 cases of definite or probable MS, providing an overall sex- and age-adjusted prevalence rate of 167.5 per 100,000. Median duration of MS from onset was 15.4 years, and median age on prevalence date was 47.5 years. The Minimal Record of Disability for MS determined the degree of impairment, disability, and handicap of the entire cohort within 4 months of the prevalence date. The frequency of Expanded Disability Status Scale scores of the MS prevalence cohort showed a bimodal distribution with peaks at 1 and 6.5 (3.5 [1 to 9.5], median [range]). Approximately one-third of the cohort had marked paraparesis, paraplegia, or quadriplegia. One-fourth of all patients needed intermittent or almost constant catheterization for bladder dysfunction. Few patients (3.7%) reported severe decrease in mentation or dementia requiring supervision. Many patients (53.1%) were working full-time. Most patients (72.2%) maintained their usual financial standard without external support. There were no differences in level of impairment, disability, or handicap observed between the subgroup of 122 patients (75.3%) who are incident cases (onset of disease as residents of Olmsted County) compared with the entire prevalence cohort. This geographically based study of MS demonstrates that the functional status is more favorable than previously recognized.

Activities of Daily Living↗

A new mouse mutant with progressive motor neuronopathy.

A new autosomal-recessive mouse mutant with progressive motor neuronopathy (pmn) is described. Homozygotes develop paralysis of the hindlimbs during the third week of life. Soon thereafter the forelimbs also become weak, and all mice die six to seven weeks after birth. Heterozygotes are normal. Skeletal muscles show neurogenic atrophy without histological signs of reinnervation. Axonal degeneration apparently starts at the endplates and is prominent in the sciatic nerve and its branches and the phrenic nerve. Axonal sprouts are abundant. There is no evidence of demyelination, and unaffected nerve fibers are normally myelinated. Sensory axons are spared. Almost all distal motor axons have disappeared in four to five weeks after birth. Ventral nerve roots show a reduced diameter of the largest fibers but no fiber deficits. The ventral horn cells show slight chromatolysis. The corticospinal tract is normal, but in terminally ill animals the fasciculus gracilis, the rubrospinal tract and possibly also reticulospinal fibers degenerate. The brain is histologically normal. The disease manifests itself in a dying-back fashion in the distal portion of the motor neurons and may represent an animal model of hereditary motor neuron diseases in man.

Animals↗